1. Field of the Invention
Exemplary embodiments of the present invention relate to a method of detecting a touch image and a display apparatus for performing the method. More particularly, exemplary embodiments of the present invention relate to a method of detecting a touch image wherein the influenced of externally provided light is significantly reduced or eliminated and a display apparatus for performing the method.
2. Description of the Related Art
Recently, a display apparatus to which information is input using light has been developed. The display apparatus typical includes a display unit and a light source unit.
A display panel of the display unit typically includes an array substrate having a thin-film transistor and a pixel electrode, an opposite substrate opposite to the array substrate having a common electrode and a liquid crystal layer interposed between the array substrate and the opposite substrate. In addition, the array substrate or the opposite substrate may include sensing elements capable of recognizing light.
The light unit may include a visible light-emitting diode (“V-LED”) or a fluorescent lamp for generating a visible wavelength light (Visible light) and an infrared light-emitting diode (“IR LED”) for generating an infrared wavelength light (“IR light”) as a light source which provides the display panel with light.
For example, the opposite substrate may include an IR transistor sensing the IR light and a visible transistor sensing the Visible light. Thus, the display apparatus may operate in a touch detecting mode using the IR light sensitive transistor and in a scanning mode using the visible light sensitive transistor.
In the touch detecting mode, the IR transistor may be driven by the IR light provided from the light source unit to be reflected by an object, and the visible transistor may be driven by external light provided from outside. In the scanning mode, the visible transistor may be driven by the Visible light provided from the light source unit to be reflected by the object.
However, in the touch detecting mode, when an amount of the external light is small, the IR transistor may detect the touch input. In addition, when the amount of the external light is large, the IR transistor may detect the touch input. However, when the amount of the external light is similar to the amount of the IR light, the IR transistor may not accurately detect the touch input.